Apparatus for carrying out high speed stirred reactions



Oct. 11, 1960 .1. v. swam-l 2,955,924

APPARATUS FOR CARRYING OUT HIGH SPEED STIRRE'D REACTIONS Filed May 23, 1955 www f?? ATTORNEYS United States Patent() i,"

APPARATUS FOR CARRYING xGUT HIGH SPEED STlRRED REACTIONS games smith, Baruesvnle, fokia., assignmto Phillips Petroleum Company, a corporation of Delaware Filed May 23, .19.155, Sel'.- NO- 51.04187 9 Claims. (Cl. 23-285) VThe present invention is directed to a means `for driving an agitator at high speed with a low speed drive shaft immersed in the liquid .to be agitated.

Mixing with its consequent blending or ,dispersion ,is often necessary to cause or hasten a reaction.- Furthermore., by :thorough mixing, undesirable side reactions ,alle .often prevented -by eliminating localized overheating or. excesses .of reagents- Solne exemples yof :reactions :which are .hastened by ,mixing or stirring are the hydrogenation of oils, the hydrolysis .of rstarches to sugars, and the liquid phase oxidation of hydrocarbons, .e.g., cyclohexarie. Many .of these reactions are also accelerated by increased pressure. The problem of providing a packing :gland which will withstand high pressures and high speedshaft rotation is one of the diiculties encountered inpromoting high pressure reactions ,by high speed stirring. Sealant materials vwhich provide' satisfactory Seal,- ing against high pressures will not withstand lthe heat generated by the friction of high speed shaft rotation, and consequently, seize or freeze up. Conversely, packing materials which will withstand a relatively high rotation speed require a small amount of ieakage to cool -the packing material, thus these materials are quite ineffective in sealing high pressure chambers.

It has now been discovered that reactions involving Lat least one liquid reactant which require high speed stirr-ing, and particularly 'those which are effected under `high pressure, may be carried out by using an apparatus which eornprises a low speed stirrer drive 4or motor, a `gear train Within .the reactor itself for .stepping up the 7low speed rotation to high speed rotation to `drive :the stirrer impeller, and feed inlets to the reactor located -Kso that incoming renctnnt feed cools Vund luhricotes the geur train- Where the temperature of the feedstock is too high to cool the gear train a coolant is circulated through the latter to effect heat exchange.

The principal object of the invention is to provide means for stirring a liquid at high speeds but employing a packing means adapted for low speed drive shafts. A further object is to provide a reactor adapted for high pressures which employs a high speed stirrer driven by a low speed drive shaft. A more specific object is to provide an agitator which can be driven at high speeds without encountering the packing gland failure normally encountered in so doing.

Referring to Figure 1, reactor vessel 1 is separated by a partition 2 into a lower or gear box portion 3 and an upper or stirring zone 5. Hollow drive shaft 14 enters the base of reactor 1 through packing gland 8 in packing housing 9. Pinion 12 is attached to shaft 14 and rotates therewith, driving gear 15 mounted on hollow impeller shaft 17, thereby rotating impeller 18. Shaft 17 is seated in a tapered roller bearing 20 and is hollow from its lower end up to a point adjacent bearing 20. A plurality of annular orices 22 in shaft 17 com municate with ports 23 adjacent the base of bearing 20. Shaft 14 is journaled in ball bearings 25, 25a and shaft 2,955,924 Patented Oct- `1 1., 19Std 17. is iournuled in hall hearing 2 6, thereby reducing tion et these 'points '.Ihe entire transmission system is cooled by admitting liquid feedstock through Shaft 14 into stirring vzone 5 and through conduit' o into gear box .3., the feed heng forced from the latter Zone into ,the upper portion ,through perforations 1 9 in partition 2 and through shaft 17, onliocs .2.2, and ports 23- This'provides internal .cooling ofthe imoeller shaft 17' and its bearing surfacestirre'd product is discharged Ytroni the top of vessel 1 through line .3.0. In an oxidation reaction; for ernrnnle,V the 'liquid ,feedstock could 'he admitted through eleruent 6'Lto l elect oooling of the hearings vand oxidizing gas adru' ed directly through shaft 14 to stirring zone 5.' 2 is n modification o f the system shown in Figure' 1. In this version'nacking gland S in packing housing 59 surrounds element 6' which is the drive shalt of .e slow .speed .inotor- 'Pinion 1 0 on shaft 1 6 rotates therewith, driving e gear train comprising gears 1 1 snd ,1 2 mounted .on shaft 1.4, and geur 1 5 mounted ou itu'- pellershntt l17'-l Shaft 14 is sented in bearings .2.5.4. and shalt 17 iin `hearings 20. 26 An external ,coolant is" admitted 4to the bearings 20. 2 5.. 25u., and 2 6 as alternative' to ,circulating the reactants through the shafts as in VFigure' 1- Liquid reactants are adrnitted to the base of. the .reactorlthrough conduits 3 17 3 2 and forced in tothe upneror stirring section entirely throughojices .1,9 inrnrtition 2., Coolant Ais adtnitted through line A34 to the onse .of reactor 1 circu1ated through internal ,ring

35 surrounding bearing 2 5, und discharged gt d- Coolant likewise ,admitted 'through ,line 38 to the interior of partition 2, circulates through rings 4 0, l1 .and is discharged from the system at'43. The circulatioh' of coolant through vertioally elongated ring 4.0 serves to simultaneously cool hoth hearings 2,6 and129the passage of 'coolant through ring .4 1 likewise cools bearing 25uln the' 'cese of en' oxidizing reaction the oxidizing' agent is preferably admitted to the stirring gone throughline 33.

It is Yevident that hv selecting -nroner gear ratios the speed .of irnreller 18 can he runde runny times the Speed o .f the drive shatt In this Wav very 'rapid Stiningcan he eifeoted oy @cooperatively slow rotation of theldrive shaft'thus avoiding the didiculties encountered in using e pecking gland around a shaft .rotating .at high speed- 'lhe'opislgratus of thisinvention Inak'cs possihle"'liigh sucedstirring o f high pressure :reaction ndritures Without the diiculty"normally'encountered with packing glands which surround high speed shafts. Packing materials such as duck rubber, an effective packing for high pressures, may be used in the packing gland on the low speed shaft of this invention without danger of seizure due to high temperatures caused by the friction of the shaft. A further advantage of the apparatus of this invention is that by changing the gear ratios any desired impeller speed can be provided while using a constant speed motor.

The foregoing illustration serves to represent a preferred embodiment of this invention but other embodiments such as means for supporting the gear train and stirrer impeller Within the reactor should be obvious to others skilled in the art. While the description given above shows the stirrer drive entering the bottom of the reactor, the drive can be positioned on either side or on the top of the reactor so long as the packing gland is exposed only to liquid, since packing glands are ineffective to stop gas leaks. Hence, if the drive shaft enters the side of the reactor it should be below liquid level; if it enters the top of a reactor the latter should be operating liquid full if the reaction is being carried out at a pressure greater than atmospheric.

I claim:

l. Apparatus suitable .for carrying out high speed stirred reactions comprising a closed pressurizable vessel having an inlet and an outlet, a partition within said vessel separating said inlet and outlet and forming a feed zone containing said inlet and a reaction zone vcontaining said outlet, said' partition havingV a, passageway'wm* municating said zones, `an impeller in'said reaction zone, a rotatableshaft carrying said impeller and Vextending through said partition into said Yfeed zone, -a drive shaft extending through the reactor'wall into said feed zone, and a speed-multiplying gear train within said feed zone linking said `drive shaft to the impeller shaft so that low rotational speed of the drive shaft imparts high rotational speed .to the impeller, said inlet being such that the incoming lfeed submerges said gear train.

' 2 An apparatus suitable for carrying out'high speed stirred reactions comprising a closed pressurizable vessel, a partitioning member within said vessel forming a reaction zone and -a feed zone, an impeller element within saidV reaction zone, a shaft affixed to said impeller element and extending into said feed zone, a packing gland in'therwall of said vessel, a drive shaft extending from outside said vessel through said packing gland into said fee-d zone, a gear train within said feed zone linking said drive shaft and said impeller shaft with a gear ratio such that low speed rotation of Vsaid drive shaft imparts high speed Vrotation :to said impeller shaft, liquid feed inlet means in said vessel and said partitioning member such that liquid feed must pass through said feed zone to said reaction zone and thereby submerges said gear Ytrain, outlet Vmeans in said vessel for removing reaction product and unreacted feed from said reaction zone, and separate reactant feed inlet means connected directly Y to said reaction zone thereby enabling chemical reaction -to-be confined to said reaction zone.

' 3. Apparatus of claim 1 wherein the drive shaft is packed with a packing designed for use with a low speed shaft. Y Y

incoming feed submerges and lubricates the gear train vand means for internally cooling. the bearings of said shafts.

6. Apparatus of claim wherein the means for cooling comprises .ducts within the several shafts designed to permit the ow of liquid reactants ltherethrough at a temperature sulcientlyllowto effect cooling of the bearing surface thereof. t

7. Apparatus of claim 5 wherein the cooling means comprises ducts extending Ithrough the interior of those portions of the support element and vessel wall which house the shaft bearings, said conduits encircling the Y bearings so as to effect indirect heart exchange therewith,

Y 'outside said vessel through said packing gland into said feed zone, a gear trainwithin said feed zone linking said drive shaft andV said impeller shaft with a .gear ratio such that low speed rotation of said drive shaft imparts high-speed rotation to rsaid impeller shaft, liquid feed inlet means in said feed zone `of said vessel and in said Vpartitioning member such that'liquid feed must pass 4. Apparatus of claim 1 wherein the drive and irn- Y peller shafts are hollow and designed to permit injection and transmission of liquid feedstock therethrough.

naled, a'packing gland VthroughV which'the drivetshaft enters the vessel, said gland being designed for use with a slow speed shaft, feed inlet means located so that the through said feed'zone torsaid reaction zone and thereby submerge said gear train, and outlet means in said reactionv zone of said vessel for removing reaction product and unreacted feed fromV said reaction zone.

9. An apparatus according to claim 8 wherein said packing vgland is positioned below the normal liquid level in said vessel.

vReferences Cited in the file of this patent UNITED STATES PATENTS A394,056 Cameron Dec. 4, 1888 1,454,610 Wolf May 8, 1923 1,514,118 Wright Nov.V 4, 1924 1,932,931 Greer et al. Oct. 31, 1931 2,028,595 Flegel Jan. 21, 1936 2,352,206 Kendall June 27, 1944 2,399,988 Cowles May 7, 1946 2,592,709Y Kinnaird Apr. 15, 1952 2,639,901 Teale May 26, 1953 2,706,667V Kaczor Apr. 19, 1955 2,731,173 Harrigan Ian. 17, 1956 

1. APPARATUS SUITABLE FOR CARRYING OUT HIGH SPEED STIRRED REACTIONS COMPRISING A CLOSED PRESSURIZABLE VESSEL HAVING AN INLET AND AN OUTLET, A PARTITION WITHIN SAID VESSEL SEPARATING SAID INLET AND OUTLET AND FORMING A FEED ZONE CONTAINING SAID INLET AND A REACTION ZONE CONTAINING SAID OUTLET, SAID PARTITION HAVING A PASSAGEWAY COMMUNICATING SAID ZONES, AN IMPELLER IN SAID REACTION ZONE, A ROTATABLE SHAFT CARRYING SAID IMPELLER AND EXTENDING THROUGH SAID PARTITION INTO SAID FEED ZONE, A DRIVE SHAFT EXTENDING THROUGH THE REACTOR WALL INTO SAID FEED ZONE, AND A SPEED-MULTIPLYING GEAR TRAIN WITHIN SAID FEED ZONE LINKING SAID DRIVE SHAFT TO THE IMPELLER SHAFT SO THAT LOW ROTATIONAL SPEED OF THE DRIVE SHAFT IMPARTS HIGH ROTATIONAL SPEED TO THE IMPELLER, SAID INLET BEING SUCH THAT THE INCOMING FEED SUBMERGES SAID GEAR TRAIN. 